The Scent of blood
by PaperPrince
Summary: Police work is not really suitable for Omegas but when has Sherlock ever cared about what is and isn't appropriate? Part of my Scent series but there's no real need to read the other parts first (Mentions of Mpreg). (Part 6 of my scent series)
1. Chapter 1

"Why on earth would I commit murder and then call the police? It's idiotic. For God's sake of course I didn't kill her! Why would I? She was teaching me mandarin. "

"You've already tampered with evidence" Points out the forensics specialist gesturing to the small boy in Sherlock's arms. "Who knows what else you did before we got here?" He says looking at Sherlock suspiciously.

Sherlock glares at him crossly and cuddles the distressed little child closer to himself. "What was I supposed to do? Leave him sitting in a pool of his mother's blood playing with the knife? " he asks.

"Wendell clam down, that's enough go bag samples or something." The policeman currently in charge of the investigation, Detective Inspector Hastings cuts in, along with another younger officer and together they create a wall effectively separating the two of them before the name calling escalates.

Hastings glances at Sherlock and smiles reassuringly. "Ignore what he said, Master Watson you're not currently being charged with anything. Although I will need a statement from you." He says getting out his notebook and a pen.

"It's Mr actually." Replies Sherlock icily, taking offence at being addressed like an un-bonded Omega, a child. He tilts his head to show off the faint scar on his neck indicating his bond.

Hasting looks at him again. "My apologies, I didn't realize." The Detective Inspector blinks. "Wait what you're bonded? ...to an Alpha? What really?" He paused. "Errr I mean don't you think you're a bit young?" The Detective looks at him worriedly.

Sherlock blinks confusedly, his friend lies dead inside her flat apparently murdered and the police want to discuss his domestic arrangements. Remembering John's advice on how to deal with idiots, he takes a breath and tries to remain calm and hide his irritation. People assuming Sherlock is younger than his actual age is an unfortunate result of having been cursed with boyish good looks. People often mistake him for Hamish's nanny after all.

"No not really, I'm 27. Can we get back to the matter at hand?"

"Is that so?" Hastings asks with an inquisitive lift of his eyebrow.  
The child in Sherlock's arms squeals, prompting Hastings to get on with his questioning.

"Right well anyway, you and the deceased were friends correct?"

"Correct, our children regularly have play dates but I don't see how it's relevant."

"I'm just trying to establish all the facts Mr Watson." Hastings says looking at his notebook. "Now you were the one to call for the police correct?"

"Yes"

"Why not call for ambulance when you found her?"

"It was unnecessary, she was already dead."

"But how did you know that?" The inspector asks bewildered.

"Detective her heart had been removed from her body, I may not be formally qualified in these matters but I do know a heart is a vital requirement of the living."

The Detective coughs, his cheeks colouring slightly. "Yes well, I think that's enough to be getting on with for now. The notebook snaps shut. "Soo Lin's mate Andy should be here soon, but for now I think it would be best if you and Zhi Zhu went and got checked over by the paramedics for shock and whatnot." Hastings says waving his hand dismissively.

Sherlock tries to speak, ask if he can assist with the case but before he knows it he is being bundled into an orange shock blanket and lead away from the crime scene by two burly Paramedics.


	2. Chapter 2

Two days later and Sherlock was beginning to lose faith in the entire police force. Not only had they failed to make any headway on the case, they were completely uninterested in anything he had to say. Moreover they refused to let him assist with the case, which was ridiculous, as Sherlock had plenty of experience solving crimes! Admittedly murder was a new one, but he was fairly confident nevertheless.

It was fortunate then that Sherlock had an ace up his sleeves. Officially all government bodies were now legally unable to deny jobs to Alpha or Omega applicants however many sectors including the police remained steadfast in the ways and traditional bigotry. As a result most worked under a sort of don't ask don't tell policy. Any officer discovered to be something other than Beta faced discrimination. Sherlock knew all this because his brother Mycroft spent a considerable amount of time and energy trying to fix this.

Anyway one of the officers dealing with Soo Lin's case just so happened to be a closeted Alpha and therefore someone Sherlock could do a deal with.


	3. Chapter 3

Gregory Lestrade glared at the lanky Omega hovering nearby and sighed around his sandwich. Normally Greg would be more than happy to help some unfortunate; however he was currently on his first break in over 24 hours so hopefully whatever he wanted could wait.

"What the hell do you want?" He asked irritably from where he sat on the cold park bench. His arse was currently freezing and he only had twenty minutes left of lunch and no time for games.

"You looking for a lost kiddy or something?" he asked bluntly.

The black haired Omega shakes his head with a smirk. "So you call yourself Greg now interesting." He mutters and instantly Greg knows he's dealing with a weird one.

"Can I help you?" He asks wondering why this odd man feels somewhat familiar.

"I need your help catching a murderer." Replies the strange man so suddenly, Greg chokes on his sandwich.

"What?" He coughs.

The Omega stares at him with bright eyes. "Your superior Hasting's thinks my friend's death was committed by a jealous lover. Which is ridiculous, he's wasting everyone's time. Neither of them showed any sign of being anything other than besotted with each other. In fact all the evidence suggests-"

Recognizing the omega from the crime scene at last Greg interrupts Mr Watson. "Now hold on, how do you know we're looking for the lover?" He questions knowing full well they hadn't disclosed any information of that sort to the public.

Mr Watson looks offended. "I'm a detective, it's what I do."

Greg shakes his head but tries not to laugh. "Leave the detecting to us alright? Police work is not the sort of thing Omegas should get involved in."

Mr Watson glares at him. "But I suppose it is a perfectly fine job for Alphas?"

Greg pales and drops the remains of his sandwich. He'd been so careful.  
Standing up he grabs the omega's scarf and pulls him close. "How do you know about that?" He hisses.

"Like I said I'm a detective, it's what I do." Mr Watson replies seeming completely unfazed despite being alone in the park trapped in a lose choke hold.

"In fact I know all about your family and that young man of yours Tobias Gregson; Omega owns a bakery but is trying to write a novel, likes cats and is currently pregnant with your child although the two of you have yet to formally bond. This is mostly due to your estrangement with your family and your desire to keep your job. I'm not amateur Greg."

Greg blinks and moves to lets go of the scarf but thinks better of it. "Are you trying to blackmail me?"

"If that's what it takes to catch a murderer then yes."

Greg sighs. "Give me one reason why should I listen to you and your theories?"

"Solving this case could get you that promotion you want and help you provide for your mate."

"And what's in it for you, what do you get out of solving this?" he asks thinking of his options.

"Justice for a friend."

Greg relents and let's go of the scarf.

"Alright tell me what you know…"


	4. Chapter 4

Childcare sorted and dressed in the suit he had worn that anniversary spent with John at a fancy hotel in the New Forest, Sherlock is ready.

With a newly convinced "Greg" on his side it doesn't take much more than a few splashes of scent neutraliser to get the police to let him into the investigation. Of course having already met, Hasting and the rest of the team know what he really is, Omega. But wearing the neutraliser makes it easier for them to ignore his basic biology and treat him like a regular. Even so Sherlock is aware he only has one shot to impress them.

Having always thought of the body as transport Sherlock can hardly believe that a few minor alterations to his appearance are all it takes for him to be taken seriously.

But even so he wastes no time explaining that Soo Lin's death must have been a professional hit. At first they think it's outrageous, but the more he explains his theories the more the evidence in front of them starts to make sense.

"In order to remove the heart the sternum needs to be partially sawed, the rib-cage cranked open, the arteries and vein cut away and then just simply hoisted out. Whoever killed her must have been a professional; it's too neat a job."

"Besides which I doubt anyone else would have gone to the bother of removing her heart after poisoning her. No the killer wanted to ensure she was really dead, so much so he took the care to bring tools with him."

"But why would someone go to all this trouble to kill an Omega?" Greg asks confused. "Were they trying to get back at her Alpha?"

Hastings snorts. "He's no background, no money, nothing. His scorecard is completely clean. I Doubt he's got it in him to make an enemy of any kind. He's as pathetically dull as Alphas come, not even fit enough for military service according to his boss at the museum."

"Mistaken identity maybe?" Greg suggests frowning at an evidence bag containing a blood splattered paper black lotus.  
Sherlock ignores most of the conversation in order to think. He stares at the photographs of the crime scene laid out on the table before him and tries to see what should be obvious. There had been something odd, something unusual at the time but if only he could remember what it was.

Sherlock stops and turns to Greg to say something but the words die on his tongue at the sight of the evidence in his hand. "Where did you find that?" He asks pointing at the flower.

Greg shrugs. "It was in her hand wasn't it?" he says handing the package over.

Sherlock examines it carefully and as he does a thought occurs. Why did the murderer having gone to such lengths to commit a near perfect crime spare the child?

Sherlock looks over the photographs once more and this time he spots it.


	5. Chapter 5

Sherlock had always been impressed by his friend's knowledge of art. Had found it fascinating how Soo Lin could just  
glance at a painting and just know who painted it and how much it was worth.

At the time he had just assumed it was a hobby of hers, just like father who enjoyed playing with model trains.

It was after all the reason her and her Alpha had met. Upon her first visit to the National Gallery she had gotten lost and accidentally ended up being locked in after hours. Thankfully she was found by a kindly security guard, her Andy, and well the rest was history.

At least that was the official story. The one she told when people asked how she and her Alpha met.

In reality Soo Lin, had been planning on stealing a priceless artefact that evening when bumbling Andy had found her. Panicked she allowed him to think she was lost. Over a cup of tea in the guard station her plan unravelled, and in the end Soo Lin left with a date instead of a painting.

From that point on she never looked back, she and Andy bonded and everything seemed fine.

Only Soo Lin was not an independent cat burglar but rather part of a gang of art smugglers called the Black Lotus.

At least that was what Sherlock had thought when he had run off ahead without any back up.

To his horror, he quickly found that the Black Lotus were involved in much more than just smuggling.


	6. Chapter 6

"When she failed to show up to the meeting point I knew something was wrong. I searched for her along with the others but there was no trace. Unable to go ahead with the heist we left without her. But I came back every year looking for her. I had to know what happened. " Zhi Zhu the elder says as he tightens the ropes around Sherlock's wrists.

"You had to know what happened to your sister." Sherlock says to try and bide some more time having already solved everything. Zhi Zhu crosses the room and picks his gun off the table.

"Yes and then when I did find her…" He says loading it with steady hands.

"She said she wanted nothing to do with you." Sherlock supplied making a note of the possible exits and the now loaded gun in the Alpha's hand.

"She said I was stupid for remaining in the gang, told me I should be ashamed of what we'd done. Of all the people we'd hurt. She threatened to tell the authorities everything unless we left her alone." The Alpha snarled from across the room.

"And you couldn't stand that could you? You couldn't stand the thought that the sister you adored, the sister you had raised and protected all these year no longer needed you, so you killed her."

"I didn't want to! She knew what would happen but she left us anyway. It wasn't my fault. None of this would have happened if she had cared about me… Besides once the General found out she was still alive I had no choice." Zhi Zhu yelled.

Rage implodes inside of Sherlock at his words. "No choice? She was your sister! Your family! You should have been on her side, protected her instead of cutting her heart out!" He says thrashing against his restraints in spite of the drugs in his system which make him sleepy.

"Shut up, shut up, shut up!" Zhi Zhu cries pointing his gun at Sherlock.

Sherlock twists and brings the chair crashing down with a bang. For a moment his world goes black before being filled by monstrous noise.

His position on the floor prevents him from seeing much of anything.

But it sounds like a rescue.


	7. Chapter 7

Sherlock is sitting in the back of an ambulance in the process of bring patched up by the medics when Greg saunters over to talk.

Sherlock rolls his eyes. "I suppose you're here to give me a stern talking to?"

"Look you just can't go rushing in like that. Not if you ever want to solve another case. You have to be much more careful. What would your Alpha say if we let you get shot eh?"

Sherlock shrugs. "He'd probably have said that I should have brought the Sig."

Greg deliberately ignores him.

"Look can I go now? It's almost bedtime and I promised I'd be there."

"Not yet, there are still a few things that don't add up," Hastings says appearing behind Greg.

"Like what?" Growls Sherlock irritably. "Zhi Zhu confessed!"

"Yes but the knife was left at the scene-"

"A miscalculation no doubt caused by sentiment" Sherlock snapped as the paramedic finished bandaging his slight head wound.

"But he left a witness."

"The child saw nothing of importance"

"But even so why run the risk?"

"Once again sentiment, the child was named after him." Sherlock replies whipping off the orange blanket from around his shoulders and standing up. Clearly done with answering questions he walks from the ambulance towards the road. He fiddles with his phone and looks both ways up and down the street.

After a moment he returns to Greg and ducks his head slightly as if embarrassed.

"Do you know where I could get a taxi from around here? My phone's dead."

"I'll give you a lift." Greg replies slapping him on the back in a friendly manner.

Sherlock hesitates, calculating something in his head.

"It's no bother." Greg grins.

"Alright, but I want to sit in the front. I'm no criminal."


	8. Chapter 8

Annoyingly it turns out the murderer had taken him just outside of London, leaving them plenty of time to talk during the drive back (even if it did explain why Sherlock didn't recognise the area).

"So Watson what's your Alpha do? Is he in the army?" Greg asks remembering the gun comment from earlier.

"I'd rather not talk about my personal life. We can talk about the case or nothing." Sherlock replies, his fingers drumming against the window.

Greg thinks for a while. "Alright, why did Soo Lin name her son after Zhi Zhu if she hated him?"

"She didn't hate him, she just couldn't allow him to be near her and her family while still a member of the Black Lotus. Zhi Zhu misunderstood. She left the gang not him. I suspect she would have welcomed him, had he left them too."

"Oh. So why'd it take so long for the brother to find her?"

"I thought that would be obvious. Zhi Zhu wasn't looking in the right places. He thought she had joined another gang not become a housewife. Moreover when an Omega bonds their scent changes to match that of their Alpha, motherhood alters the scent further. They no longer smell of the pack they were born in but of the pack they have created. He could have been in the same vicinity multiple times and still not recognised her."

Greg snorts. "Oh come on that's just baloney isn't it?"

Sherlock eyes turn sharp.

"Is it really brother?"


	9. Chapter 9

Greg nearly crashes the car in shock. He doesn't, because he is a bloody good driver but it is a near thing. Wordlessly he pulls up on the side of the road. He turns the engine off before daring to look at Sherlock. They spend the minute silently reading each other's face, deducing what they can from each other.

Greg gapes at the mad genius who had earlier blackmailed him. Sherlock stares back unfazed. He seems to be telling truth. Greg swears. He then swears again. It didn't help as much as he thought it would.

"What did you say?" He yells his heart hammering as he manages to regain control of the car.

"What's the matter Sherrinford? Don't you remember me?" Sherlock asks pointedly.

"But your name's Watson! Lock Watson."

"Lock is short for Sherlock. I changed my surname when I bonded. Anyway it's better than Greg."

"But you're an Omega! I always thought Shirley would end up an Alpha like me and My." Greg says before his brain can tell him it is a bad idea.

"It's been over twenty years, of course there's going to be things you didn't know. Besides what's wrong with being an Omega?" Sherlock says defensively.

"Um so it was a left here right?"

"The car is not currently moving Greg." Sherlock says as he elbows him in the ribs. "God I'd forgotten you were such a prat." He huffs as he bunkers back into his seat to stare outside the window.

"Hey, no, I didn't mean. Sherlock, I didn't mean to- upset you. It's fine. More than that even, I'm just surprised. Christ, I dunno… it's just you were always so goddamn bossy"

"Just shut up and take me home, Greg."


	10. Chapter 10

Greg dutifully pulls up opposite Speedy's café and Sherlock is halfway out the door yelling "Laterz" before Greg can stop him.

"Wait!" Greg calls grabbing his shoulder. "Do you think I could come in for a bit?" He asks cautiously, well aware how protective Omegas could be of their Den.

Sherlock thinks of mummy waiting at home and how the shock of the prodigal son's return might affect her. He looks at Greg fretfully and quickly finds his voice. "A deal's a deal remember? I won't tell anyone your secret."

"Great, that's um good to know. But don't you want to talk or something? I mean there's so much to catch up on. If you think about it I don't know anything about you really."

Sherlock turns and pulls himself back into the car. "And whose fault it that?" He snaps. "You're the one who ran away and left."

"Sherlock I had to-"

"Had to what? Hide who you are to make it in this world because you couldn't cut it being yourself? Had to hurt everyone who loved you and let them wonder if you were alive or dead for over twenty years?" Sherlock screeches bitterly.

"You think it was easy for me?" Greg retorts. "I was just 14; do you know what options I had at the time? None! I didn't want to end up a pawn in the system so I got out. I did what I did to get to where I am today."

Greg takes a deep breath and puts his hands on the steering wheel calming himself. "But I thought about what I did every day. I wanted to come back home. Only the longer I left it the harder it was you know?"  
Sherlock shakes his head dumbly.

Greg sighs. "I finally went home about six months ago only it wasn't there anymore. No one was."


	11. Chapter 11

Sherlock's anger dissipates slightly at the look upon Greg's face. The words "We moved" tumble softly from his lips. And even though it is late and Greg isn't forgiven just yet, Sherlock finds himself inviting his brother inside for some tea.

Sherlock belatedly realises that this is probably a truly awful idea upon unlocking the front door to find father sitting on the stairs in the hallway waiting for him.

Sherlock pauses uncertainly in the dim hallway which is lit only by the light creeping from the first floor.

"Welcome home 'Lock." Siger declares smiling as he stands up and moves to hug his youngest.

"You waited up for me?" Sherlock inquires upon noticing his father's stiff movements which indicate he had been sitting a fairly long time on the hard stairs.

"Yes, I tried texting you earlier, but you didn't reply so I was worried. Your mother and I put the little ones to sleep already. I trust you caught the murderer?"

Sherlock nods awkwardly against his shoulder, aware that Greg is still outside on the step.

"Good, I'm glad. She can rest properly now poor lass." Siger says ruffling Sherlock hair slightly before letting go of Sherlock completely.

"Did you eat while out? I think there's some pasta bake left-" Distracted father stops mid-sentence and looks towards the half open door.

"Whose with you Lock? The scent's familiar- is John back?"

"No it's not John…" Greg replies pushing the door back to reveal himself.

Siger stares at him disbelievingly for a very long time. Unsure of his father's reaction Greg holds his ground but makes no move to invade their territory. Not wanting to offend Greg bows his head and Siger dips his chin in recognition. For a while they just stare at each other, analysing like Sherlock had done earlier.

Siger finds his voice first.

"Son are you going to stand there all night in the cold or are you going to come in?" He snaps striding forward and embracing Greg in a tight hug without warning.

"Just wait until your mother sees you."

-End

* * *

Okay so this is the end of this fic but don't be sad as I still plan on having Sherlock have a few more kids.


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